Those radioactive fission products occuring in liquid form in the first extraction cycle of a reprocessing facility are usually fixed in glass since glass constitutes a mechanically stable product and the radionuclides are held tightly together thereby.
The glass fixing or vitrifying facility is fed with the highly radioactive fission-product solution in the conventional manner from a feed container in measured quantities. The feed container is charged from a ready receiver container for radioactive fission-product solutions which are to be processed.
Offgases occur during the vitrification of fission-product solutions in the melting oven of the glass-fixing or vitrifying facility. These offgases have to be freed from entrained radioactive dust particles and the like since the conduits and components would otherwise become blocked. It is therefore the conventional practice to pass the offgas through an offgas scrubbing stage for separating the dust particles therefrom. The offgas is scrubbed in this scrubbing stage in a counterflow of scrubbing liquid in which separated acids, dust particles and aerosols accumulate. Such an offgas scrubbing stage is shown in FIG. 3 of DE-AS 21 25 915 wherein the scrubbing column is designated by reference numeral 14. A pump 19 regulates the flow of liquid through the scrubbing column 14.
The scrubbing liquid is conducted in a circulatory system in order to minimize the occurrence of radioactive secondary waste. After a predetermined time, the scrubbing liquid becomes heavily contaminated and must be exchanged.